Great apes as models for human evolution

As the genomically closest living beings to contemporary humans (Homo sapiens), bonobos (Pan paniscus), chimpanzees (Pan troglodytes), gibbons (Hylobatidae), gorillas (Gorillaspp.), and orangutans (Pongospp.) are obvious first choices for modeling what ancestral Hominidae looked like, how they behaved, and the extent to which they retain humanoid characteristics. Although Pliocene fossil hominoids are useful for testing ideas about which extant apes are reliable regarding some physical features of emergent hominids, one is reduced to writing scenarios regarding most behavioral traits that apes and hominids had or have in common or are evolutionarily divergent.